Bicycle frame



FIG. 1 is a perspective view of a bicycle frame showing my new design;

FIG. 2 is an enlarged front elevational view thereof;

FIG. 3 is an enlarged rear elevational view thereof;

FIG. 4 is an enlarged left side view thereof;

FIG. 5 is an enlarged right side view thereof;

FIG. 6 is an enlarged top plain view thereof;

FIG. 7 is an enlarged bottom plain view thereof; and,

FIG. 8 is a view showing the application thereof, wherein the broken line portion is for illustrative purpose only and forms no part of the claimed design. 

The ornamental design for a bicycle frame, as shown and described. 